Yamaha YZF-R125 Owners Manual: Ignition circuit cut-off system
The ignition circuit cut-off system (comprising the sidestand switch, clutch switch and neutral switch) has the following functions.
- It prevents starting when the transmission is in gear and the sidestand is up, but the clutch lever is not pulled.
- It prevents starting when the transmission is in gear and the clutch lever is pulled, but the sidestand is still down.
- It cuts the running engine when the transmission is in gear and the sidestand is moved down.
Periodically check the operation of the ignition circuit cut-off system according to the following procedure.
WARNING
If a malfunction is noted, have a Yamaha
dealer check the system before riding.
Sidestand
The sidestand is located on the left side
of the frame. Raise the sidestand or
lower it with your foot while holding the
vehicle upright.
TIP
The built-in sidestand switch is part of
the ign ...
For your safety - pre-operation checks
Inspect your vehicle each time you use it to make sure the vehicle is in safe
operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner's Ma ...
Other materials:
Checking the starter motor operation
1. Check:
Starter motor operation
Does not operate → Perform the electric
starting system troubleshooting, starting with
step 4.
Refer to "TROUBLESHOOTING" on page
8-9.
a. Connect the positive battery terminal "1" and
starter motor lead "2" with a jumper lead "3".
W ...
Checking the radiator fan motor
1. Check:
Radiator fan motor
Faulty/rough movement → Replace.
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
Positive tester probe →
blue "1"
Negative tester probe →
black "2"
c. Measure ...
Checking the cylinder head
1. Eliminate:
Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damaging
or scratching:
Spark plug bore threads
Valve seats
2. Check:
Cylinder head
Damage/scratches Replace.
Cylinder head water jacket
Min ...